Fuel dispensing nozzles are widely used and understood in the field. Fuel nozzles are used for directing and regulating a flow of fuel into a container to be filled. Typical fuel nozzles are comprised of a nozzle body, a valve assembly for regulating fuel flow, and a tubular spout.
Recently, significant attention has been directed to the adverse environmental effects caused by fuel dispensing nozzles. Fuel nozzles create vapors that contain volatile organics that chemically react with nitrogen oxides to form ground level ozone, often called “smog”. Ground level ozone can potentially cause irritation to the nose, throat, lungs and bring on asthma attacks. In addition, fuel vapors contain other harmful toxic chemicals, such as benzene.
Fuel dispensing nozzles provide several significant sources of fuel vapors, including: vapors displaced from containers as liquid is inserted; fuel dripped from nozzle spouts; and, residual fuel left on spouts after a fueling cycle.
The most predominant source of fuel vapors has been addressed through the implementation of vapor recovery systems, such as described by U.S. Pat. No. 5,213,142. Typical vapor recovery systems dispense fuel though a main tube of a spout and vacuum vapors through a secondary spout channel. Although vapor recovery systems can significantly reduce the amount of vapors that reach the atmosphere, the technology is expensive to install and operate, and thus has been implemented in limited areas. In addition, vapor recovery systems do not address the sources of dripping fuel or residual fuel.
The issues of fuel dripping and residual fuel have largely been either ignored, or inadequately addressed by equipment manufacturers. To force manufacturers to develop technology that reduces these emissions, the California Air Resource Board (CARB) has implemented a series of new requirements that must be met by nozzle manufactures. The new requirements are implemented through a series of “Phases”. One of the CARB requirements is that a fuel nozzle shall produce no more than one post fueling drop. Another requirement limits the amount of residual fuel that can be retained by a nozzle and hose assembly after fueling.
Many new drop reducing spouts have been created, such as: U.S. Pat. No. 5,602,364 and U.S. Pat. No. 5,645,116. Although these valve systems may reduce the amount of drops that occur, they are unlikely to consistently meet the requirements set forth by CARB. A problem with “dripless” technologies, such as listed above, is that they do not eliminate the drip creating residual fuel from the outside surfaces of the spout. In addition, the “dripless” features themselves have surfaces that can attract liquid fuel and increase the potential for drops. Many “dripless” spouts may eliminate unallowable drops in one test run, and then have one or more unallowable drops in subsequent test runs performed in the same fashion and with the same nozzle.
Another problem with existing nozzle technologies, such as described above, is that they do not typically work with existing “standard” (non-vapor recovery) type nozzles. These “standard” nozzles are used in a large percentage of fueling stations which are not located in highly populated areas or do not dispense large volumes of gasoline.
Yet another problem with existing nozzle technologies is that they require significant change-over costs. Many of the aforementioned designs require that at least a complete new nozzle be installed in order for their benefits to be realized.
In these respects, the improved nozzle endface surface according to the present invention substantially departs from conventional concepts of the prior art, and in doing so provide an apparatus primarily designed for the purpose of reducing the amount of vapor that reaches the atmosphere during a fueling cycle.